During the paper manufacturing process, as the paper web comes out of the drying section of the paper machine, the paper web is typically wound into a large roll. The winding process typically involves continuously and repeatedly turning the paper web about a central shaft as the web comes out of the drying section of the paper machine. Once complete, these large rolls are commonly called “parent rolls.” The process of initially winding paper into parent rolls allows the manufacturer to quickly and efficiently package large quantities of paper as it is produced by the paper machine.
Even so, paper manufactures do not always sell the parent rolls to their customers. Sometimes the manufacturers' customers wish to purchase smaller rolls of paper or other finished products such as paper towels and tissue paper. In such instances, the paper manufacturer uses downstream equipment to create the smaller rolls or to otherwise process the paper into these smaller products.
An important aspect of processing these parent rolls is changing from an old, spent parent roll, to a new full parent roll with as little down time as possible and preferably without stopping the downstream processing equipment. Therefore, the flying splice was developed. In a flying splice system, two or more unwind stands feed a web into the downstream processing equipment. The unwind stands each unwind a web into a splicing area and then to the downstream equipment. A first unwind stand may unroll its parent roll while the other is loaded with a full roll. When the parent roll on the first unwind stand is exhausted or nearly spent, the second unwind stand may start to unwind a second parent roll into the splice area. Once the second parent roll is being unwound, the first parent roll may be replaced by another full roll so that it is ready to be unwound when the second roll is nearly spent.
In paper products in general, and tissue products in particular, each side of the web may have different properties and manufacturers may want to maintain the orientation of these different sides of the web when switching between parent rolls. To maintain the orientation of the paper web between rolls, one unwind stand may have to unwind the web from the bottom of the parent roll, while the another unwind stand may have to unwind the web from the top of the parent roll. For example, in FIG. 1 a parent roll may be unwound from the bottom to cause Side A of its web tail to be on the right and Side B to be on the left as the web tail enters the splicing area, whereas another parent roll may be unwound from the top to cause Side A of its web tail to be on the right and Side B to be on the left as the web tail enters the splicing area.
As a result, the manufacturer unwinds the large parent rolls so that the paper can be rewound into smaller rolls or otherwise processed by other, downstream, equipment. The unwinding of the parent roll generally occurs in an unwind stand and is essentially accomplished by rotating the parent roll in a direction opposite to that used to initially wind the paper web onto the shaft of the parent roll.
Once a portion of a first parent roll, which is unwound from the bottom, is unwound and a second parent roll is unwinding and feeding the downstream equipment the paper web of the first parent roll may be cut. Typically, the paper web is cut across its width, in a cross-machine direction. When the cut is made, a tail is created on the parent roll. The tail consists of the unwound paper web located between the parent roll and the location of the cut. The tail may then be rewound onto the parent roll and the parent roll may be ejected from the unwind stand.
During the ejection process, however, the parent roll may sometimes roll in a direction that causes the tail to unwind from the parent roll and trail on the ground, particularly when the parent roll was unwound from the bottom. When this happens, it is not unusual for fifty feet or more of tail to accumulate on the ground. The unwound portion of the tail may then be rewound onto the parent roll or cutoff, picked up, and discarded. Both of these processes take time and manpower, and cause delays in the unwind process.
Accordingly, current parent roll rewinding and ejection processes could benefit from improved techniques and devices that greatly reduce or eliminate the waste and inefficiencies associated with paper tails created during the unwind and ejection process.